Our proposed research is in the area of ocular angiogenesis (neovascularization), a key pathology in many serious eye diseases. We wish to investigate differential angiogenesis in the mouse eye, that is, angiogenic processes that may vary, depending on organ site (retina, choroid, iris, cornea) or angiogenic stimulus (cytokines, growth factors, tumors). The endothelial cell, the cell that lines blood vessels and comprises the totality of capillaries, rather than being passive and uniform as was once thought, is a cell of exquisite specificity, highly active and interactive, and there has been a veritable explosion of current research documenting these heterogeneities. Recent studies in our laboratory and others have shown that the angiogenic process, that sequence of events leading from breakdown of extracellular matrix, movement and proliferation of endothelial cells to three-dimensional structuring of new vessels, also is a heterogeneous process depending on tissue specificity and type of angiogenic stimulus. We wish to document these differences carefully in the mouse eye with the ultimate aim being the development of new treatment and prevention strategies for neovascularization in eye disease. Our specific aims are: 1. To validate the concept of differential angiogenesis in the eye. This will be achieved by comparing the response of blood vessels in the retina, choroid, iris, limbus and cornea. Inducers of angiogenesis will include inflammatory cytokines, growth factors, tumor cells and immune effector cells. 2. To establish endothelial cell lines from retina, choroid, iris, limbus and cornea. Endothelial cells will be isolated both from the normal quiescent vasculature and from vessels formed during neovascularization. 3. To assess the in vitro reaction of these cell lines by their response to inducers of neovascularization, monitoring cell surface phenotype and functional behavior, 4. To analyze the effect of different antiangiogenic agents in vivo and in vitro, comparing the response of different segments of the eye in vivo and of the different endothelial cell lines derived from these sites in vitro. To accomplish these aims we will use a combination of cell culture procedures, flow cytometry, cell sorting, confocal microscopy, assessment of cell motility, immunocytochemistry, fluorescence microscopy, image analysis and specialized small animal eye surgery.